Combined Selective Hydrogenation and Catalytic Cracking Process for Efficient Conversion of Heavy Cycle Oil to High Octane Number Gasoline

Heavy cycle oil (HCO) is difficult to be converted into gasoline via fluid catalytic cracking (FCC) or hydrotreating. Abundant polycyclic aromatic hydrocarbons in HCO lead to condensation coke and high H-2 consumption. To efficiently convert HCO, in this work, HCO was selectively hydrogenated first and then cracked in an FCC unit. For the ideal molecular structure of naphthenoaromatics cracking after HCO selective hydrogenation, tetralin-type naphthenoaromatics were the desired products by the FCC test of model compounds. The effect of hydrogenation extent on structural composition was analyzed to confirm the optimal hydrogenation extent of HCO. The catalytic cracking results of hydro-HCO (Hy-HCO) indicated that the research octane number of FCC gasoline from selective hydrogenation is up to 96.5. Compared with HCO, the conversion and gasoline yield increased significantly, and the yields of heavy oil and coke decreased. Finally, the FCC operation conditions of Hy-HCO were investigated to enhance cracking efficiency.